Piston Ring Break-In. Agree or Disagree?

[VortecCPI]

What does everybody think about this:  http://www.mototuneusa.com/break_in_secrets.htm

 

With today's harder ring materials it sure seems to make sense to me.

 

Per Wiseco:

 

The 25787XA rings are:

• Top ring: Alloy steel ferox coated, chrome faced
• 2^nd Ring: Nodular iron, phosphate coated, taper face (no face coating)
• Oil set: Stainless steel spacer, alloy steel rails with chrome face

 

EDIT:  Per Chuck's response I'm asking/posting only in the context of the 150/200/230 engines

Edited March 2, 2015 by VortecCPI

[Chuck.]

My advice for ring breakin is to go by what the  piston/ring mfg says for their piston/rings and your cylinder, that includes cylinder prep, hone, and assembly method.

 

I discount one method fits all because there is such a variety of bore and piston/ring materials, along with ring material and bore prep.  What works for a cast piston in an iron bore is a lot different than a forged piston in a Nikasil bore. 

 

For example we have in motorcycles:

Cast, forged, and coated  pistons.

Iron and aluminum cylinders.

Iron & steel bores, Nikasil and chrome plated bores.

And who knows how many different rings.

 

I agree it is combustion pressure that seats the rings but his recommended hard breakin ignores a lot of variables that could create problems. The slow breakin processes from the old days were based on assembly tolerances of the day.  With the newer mfg methods and tolerance controls some engines are ready for prime time on first start. 

Edited March 3, 2015 by Chuck.

[adnohguy]

What does everybody think about this: http://www.mototuneusa.com/break_in_secrets.htm

With today's harder ring materials it sure seems to make sense to me.

Per Wiseco:

The 25787XA rings are:

• Top ring: Alloy steel ferox coated, chrome faced
• 2^nd Ring: Nodular iron, phosphate coated, taper face (no face coating)
• Oil set: Stainless steel spacer, alloy steel rails with chrome face

EDIT: Per Chuck's response I'm asking/posting only in the context of the 150/200/230 engines

Multiple 233- 247cc builds ....No issues yet, 600 grit Sunnen hone, assemble piston into cylinder with WD 40. Electric start with spark plug out until your non synthetic oil pressure is verified, complete engine warm up, drive it like you stole it up through all gears and back down through all the gears several times, drain oil, refill with the oil of choice that you intend to use from now on....(synthetic or not) done, Good to go.

My Pistons show absolutely no blow-by past the rings at all. Just like the photos on Mototune.

Works on 2strokes also. I was building many Honda TRX 250r's from 1986-2005 (250cc up to 370cc)

[VortecCPI]

Multiple 233- 247cc builds ....No issues yet, 600 grit Sunnen hone, assemble piston into cylinder with WD 40. Electric start with spark plug out until your non synthetic oil pressure is verified, complete engine warm up, drive it like you stole it up through all gears and back down through all the gears several times, drain oil, refill with the oil of choice that you intend to use from now on....(synthetic or not) done, Good to go.

My Pistons show absolutely no blow-by past the rings at all. Just like the photos on Mototune.

Works on 2strokes also. I was building many Honda TRX 250r's from 1986-2005 (250cc up to 370cc)

 

Awesome!  Thank you!  That was my plan except I was going to do maybe 30 minutes of very hard laps around the short test track.  Do you think that is too long before the first oil change?

 

Seems like I may have already asked you this or you already mentioned it in another post.  If I did I apologize.

[atown8605]

My 2 cents: do the first oil change as soon as possible.

[SteveThe Snakes]

The big issue is not break in.

It's who bored and honed the proper clearance or over bored and got a sloppy piston clearance.

[Gary C]

The question is: Piston RING break in.

Not big bore break in or cam break in motor overhaul break in or any other combination.

My answer is, YES Mototune break in (IF you know the jetting is correct) go for it!!

ive been seating rings this way for many years and no blowby ever.

[adnohguy]

Awesome! Thank you! That was my plan except I was going to do maybe 30 minutes of very hard laps around the short test track. Do you think that is too long before the first oil change?

Seems like I may have already asked you this or you already mentioned it in another post. If I did I apologize.

Yep that will do it, you will be just fine.

[Chuck.]

I've seated rings both ways; several heat cycles with increasing engine loads, and more aggressive.  Both were based on ring mfg recommendation and other components that may have required special breakin such as a solid lifter cam.

But always a oil change after the first heat cycle.

 

I know this is a sub 250 two valve forum for engines with steel bores and my last build used a forged piston, was assembled dry and went thru two heat cycles before trail riding, but it had a new high lift cam that needed breakin.  Then several trail rides without max rpm but plenty of acceleration events to help seat the rings.  That engine still runs great 5 years later.

 

I also have a CRF250X with a Nikasil bore and rebuilds involve cleaning the bore, then new rings, and sometimes a new piston. According to the Service Manager at the local Honda dealer assemble it dry and ride.  They use a ball hone to clean the bore, it isn't hard enough to cut new hone marks. The alternative is ScotchBrite with soap and water along with lots of elbow grease until the bore is shiny silver. The Honda pistons are forged with a single compression ring and coated.

Edited March 3, 2015 by Chuck.

[VortecCPI]

More interesting history here:  http://www.klemmvintage.com/breakin.htm

 

Not in the context of 150/200/230 but still a bit interesting...

Edited March 3, 2015 by VortecCPI

[davek18]

I assemble them dry and have for many many years on the hundreds of different engines I have done, motorcycle both 2 and 4 stroke, cars, lawn mowers, you name it.  Not a seizure or oil burner of smoker in the bunch.  Leakdown at 5% or less when checked.

 

Oh, and I never hone a cylinder except for clearance after boring.  Not needed on re-ring.

 

I do a couple of fairly hard runs initially with cool down between if I can.

 

Chromed rings in a nikasil bore you might want to lightly coat with a dry moly lube, but most others just clean and dry.

[VortecCPI]

I assemble them dry and have for many many years on the hundreds of different engines I have done, motorcycle both 2 and 4 stroke, cars, lawn mowers, you name it.  Not a seizure or oil burner of smoker in the bunch.  Leakdown at 5% or less when checked.

 

Oh, and I never hone a cylinder except for clearance after boring.  Not needed on re-ring.

 

I do a couple of fairly hard runs initially with cool down between if I can.

 

Chromed rings in a nikasil bore you might want to lightly coat with a dry moly lube, but most others just clean and dry.

 

So no hone when re-ringing with chrome-faced rings?

[davek18]

I wouldn't. 

 

I have been employed as a mechanic since '72, first on bikes, then Honda cars in '78.  I now own my own shop working on import cars with 4 employees.  Opened the doors in '84.  I have not assembled a cylinder wet since '75.  I had heard the no-hone  theory and had tried it on my own stuff with success.  When Honda informed us in '79 that it was unnecessary that clinched it.  I quit honing on a normal re-ring, as did the other techs in the shop at the time and literally most others I have worked with since, once they see it works well.

 

If a cylinder is scored badly or seized I will hone it to clean the stuck metal off, or true it a little, but those are pure patch it back together jobs.  If it is scored it is wasted anyway and needs a rebore.  After reboring  a rigid hone is needed to clean up the boring marks and clearance the piston.  Usually you can still see the original hone marks in a cylinder that you are re-ringing, at least on the imports we work on.  On a side note on import cars if you do rebore the cylinders you cut through the original factory hard surface and you will likely have very poor longevity on that engine.

[SteveThe Snakes]

Hum a billion Honda's and Yamaha's etc.being sold and used by the general public. All installed with oily pistons at the factory and all break in just fine.

 

The usual difference who did the bore and hone.

[davek18]

I was told by Honda back when I worked on the bikes that the bikes were fully assembled and run around a test track, then disassembled for crating and shipping.  I am sure they got run ever so gently on that initial ride.  What would you do if you were the one responsible to approve it for shipping? 

 

They came out of the crate running good and no smoke on startup.

[SteveThe Snakes]

I use to be a set up guy at the dealer and a dealer mechanic a hundred years ago. I believe they run them on a dyno to simulate running and it would be gentle. We were to test flog them once set up around the street. We were told to go easy well expect for the guys that never rode a CR250.

[davek18]

We never went easy on them.  One salesman in particular that bought a lot of bikes over the years would set them up himself, add fluids and battery if there was one, and then on first fire it went down the street full throttle immediately.  All of his bikes ran great overall.  He even had the only first gen GL1000 that didn't smoke on restart after sitting on the sidestand.  We re-ringed a couple of those for chronic complainers under warranty.

[VortecCPI]

We never went easy on them.  One salesman in particular that bought a lot of bikes over the years would set them up himself, add fluids and battery if there was one, and then on first fire it went down the street full throttle immediately.  All of his bikes ran great overall.  He even had the only first gen GL1000 that didn't smoke on restart after sitting on the sidestand.  We re-ringed a couple of those for chronic complainers under warranty.

 

You may like this post:  https://www.thumpertalk.com/topic/1121345-deglazehone-or-not

[VortecCPI]

This has again become an interesting topic of discussion.  My father put chrome-faced rings in his 76 Toyota Land Cruiser without honing the cylinders first and they never seated right.  We figured it was due to the fact is was not honed but perhaps it was due to the very mild break-in that caused it.  It had plenty of power and didn't blow any smoke but it used oil from that point till the day it was sold.

 

As children we put new rings in our old XL125 without honing and that worked fine.  My brother got on it and beat as usual and it was fine.

Edited March 3, 2015 by VortecCPI

[davek18]

This always seems to spark a lively discussion, and I will stop now so as not to be trollish.   I will suffice it to say however that i have assembled hundreds, possibly even thousands of cylinders dry with no hone, and if you compound that with the techs I have worked with in shops over the years......

 

Most of these were automotive I admit but they were predominantly imports, which are a different breed alright from the domestic stuff.